JP2018159859A - Photosensitive resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition capable of bonding semiconductor elements to each other while maintaining patterning properties, and to provide a semiconductor device which includes a laminated semiconductor element obtained by bonding semiconductor elements to each other with the photosensitive resin composition, has high reliability, and is easy to manufacture.SOLUTION: The photosensitive resin composition contains (A) an alkali-soluble resin having a functional group exhibiting Bronsted acidity by proton dissociation, (B) a photoacid generator, (C) a thermal crosslinking agent, and (D) an alkoxysilane compound. The alkoxysilane compound (D) has an aromatic ring, and a functional group exhibiting reactivity with the functional group exhibiting Bronsted acidity by proton dissociation is directly bonded to the aromatic ring.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a photosensitive resin composition and a semiconductor device.

Conventionally, a polybenzoxazole resin, a polyimide resin, a phenol resin, or the like having excellent heat resistance and mechanical properties has been used for a surface protective film of a semiconductor element. On the other hand, in order to simplify the process, a positive photosensitive resin composition in which a polyazoxazole resin, a polyimide resin, a phenol resin, or the like is combined with a diazoquinone compound as a photosensitive agent is also used. This photosensitive resin composition becomes hardly soluble in an alkaline aqueous solution in the unexposed portion due to the effect of inhibiting the dissolution of the diazoquinone compound in polybenzoxazole resin, polyimide resin, phenol resin, and the like. On the other hand, in the exposed area, the diazoquinone compound undergoes a chemical change, and the photosensitive resin composition becomes soluble in an alkaline aqueous solution. By utilizing the difference in solubility between the exposed portion and the unexposed portion and dissolving and removing the exposed portion with an alkaline aqueous solution, it becomes possible to create a coating film pattern of only the unexposed portion (alkali development).

  When these photosensitive resin compositions are applied to a surface protection film of a semiconductor element or an adhesive between semiconductor elements in a stacked semiconductor device, the important resin characteristics are circuit patternability and adhesion to a wafer. . If the photosensitive resin composition has low sensitivity to irradiation light, the exposure time becomes long and the process throughput (processing speed per unit time) decreases, so a material with higher sensitivity is required. Moreover, when the adhesiveness of the photosensitive resin composition and a wafer is inadequate, when patterning by alkali image development, the problem that a pattern of an unexposed part peels with melt | dissolution of an exposed part will arise. When such a problem occurs, particularly when these photosensitive resin compositions are applied to an adhesive between semiconductor elements in a stacked semiconductor device, the semiconductor element is bonded to each other through the adhesive. Adhesiveness (adhesiveness) between elements decreases, and as a result, the mechanical and electrical reliability of the semiconductor device decreases.

  These photosensitive resin compositions have an alkoxysilane compound that improves the mutual adhesion by mediating the chemical bond between the base polymer of the photosensitive resin composition and the wafer surface in order to ensure adhesion to the wafer. A coupling agent typified by may be added. Even if a coupling agent is not added, the adhesion to the wafer can be ensured as in Patent Documents 1, 2, and 3, but in recent years, when the coating film is heated and cured after patterning, curing at a lower temperature is possible. Since it is required, it tends to be more difficult to ensure adhesion. Therefore, in recent years, development of a photosensitive resin composition containing an appropriate amount of an appropriate coupling agent has been desired.

JP 2000-206688 JP-A-10-69073 JP-A-11-194497

  An object of the present invention is to provide a photosensitive resin composition having patterning properties while ensuring adhesion to a wafer, and a laminated semiconductor device in which semiconductor elements are bonded to each other by a cured product of the photosensitive resin composition. It is to provide.

As a result of intensive studies by the present inventors, by adding an alkoxysilane compound having a specific chemical structure as a coupling agent to the photosensitive resin composition, both good adhesion and patternability can be achieved in a stacked semiconductor device. I found out. That is, the said subject is solved by invention of following (1)-(8).
(1)
(A) an alkali-soluble resin having a functional group showing Bronsted acidity by proton dissociation;
(B) a photoacid generator;
(C) a thermal crosslinking agent;
(D) an alkoxysilane compound;
A photosensitive resin composition comprising:
The (D) alkoxysilane compound has an aromatic ring, and the functional group showing reactivity with the functional group showing Bronsted acidity by proton dissociation is directly bonded to the aromatic ring. Resin composition.
(2)
The photosensitive resin composition according to claim 1, wherein the (D) alkoxysilane compound is represented by the general formula (1).

In the above general formula (1), X is a carbon atom or nitrogen atom, R ₁ is a functional group showing reactivity with a functional group showing Bronsted acidity by proton dissociation, R ₂ is an alkylene group having 1 to 10 carbon atoms, R ₃ and R ₄ represent an alkyl group having 1 to 3 carbon atoms, and t represents 0 to 3.
(3)
The photosensitive resin composition according to claim 1, wherein the (D) alkoxysilane compound is represented by the general formula (2).

In the above general formula (2), X is a carbon atom or a nitrogen atom, R ₁ is a functional group showing reactivity with a functional group showing Bronsted acidity by proton dissociation, R ₂ is an alkylene group having 1 to 10 carbon atoms, R ₃ and R ₄ represent an alkyl group having 1 to 3 carbon atoms, and t represents 0 to 3.
(4)
The photosensitive resin composition according to claim 1, wherein the thermal crosslinking agent (C) is a compound having a glycidyl group.
(5)
The photosensitive resin according to any one of claims 1 to 4, wherein the alkali-soluble resin (A) having a functional group that exhibits Bronsted acidity by proton dissociation is a norbornene monomer homopolymer or copolymer. Composition.
(6)
The functional group of the alkali-soluble resin having a functional group that exhibits Bronsted acidity by proton dissociation (A) is a carboxyl group or —C (OH) — (CF ₃ ) _2. The photosensitive resin composition according to item.
(7)
The semiconductor element using the hardened | cured material of the photosensitive resin composition as described in any one of Claims 1 thru | or 6. (8)
A stacked semiconductor device in which the semiconductor elements according to claim 7 are stacked.

  By using the cured product of the photosensitive resin composition of the present invention, it is possible to obtain a semiconductor element having patterning properties while ensuring adhesion to the wafer, and a defect due to interface peeling between the semiconductor element and the photosensitive resin composition Is less likely to occur, and the mechanical and electrical reliability of the semiconductor device can be improved.

  Further, by using the cured product of the photosensitive resin composition of the present invention, a stacked semiconductor device in which semiconductor elements are bonded with high mechanical and electrical reliability can be obtained.

It is sectional drawing which shows an example of the semiconductor device of this invention. It is a figure for demonstrating the method of manufacturing the semiconductor device shown in FIG. It is a figure for demonstrating the method of manufacturing the semiconductor device shown in FIG. It is a figure for demonstrating the method of manufacturing the semiconductor device shown in FIG. It is a figure for demonstrating the method of manufacturing the semiconductor device shown in FIG.

  Hereinafter, the photosensitive resin composition of the present invention and the method for producing a semiconductor device will be described in detail based on preferred embodiments shown in the accompanying drawings.

<Semiconductor device>
First, an example of the semiconductor device of the present invention will be described.

  FIG. 1 is a cross-sectional view showing an example of a semiconductor device of the present invention.

A semiconductor device 10 shown in FIG. 1 is an example having a BGA (Ball Grid Array) type semiconductor package, a plurality of stacked semiconductor chips 20 (semiconductor elements), and an adhesive layer 601 for bonding the semiconductor chips 20 to each other. The package substrate 30 that supports the semiconductor chip 20, the adhesive layer 101 that bonds the semiconductor chip 20 and the package substrate 30, the mold part 50 that seals the semiconductor chip 20, and the solder that is provided below the package substrate 30 And a ball 80. Hereinafter, the configuration of each unit will be described in detail.

The semiconductor chip 20 may be any kind of element, for example, NAND (Not AND
) Flash memory, memory elements such as DRAM (Dynamic Random Access Memory), integrated circuit elements such as IC (Integrated Circuit) and LSI (Large Scale Integration).

  The constituent material of the semiconductor chip 20 is not particularly limited, and examples thereof include single crystal materials such as silicon, silicon carbide, and compound semiconductors, polycrystalline materials, and amorphous materials.

The plurality of semiconductor chips 20 are stacked slightly shifted from each other in the in-plane direction, thereby forming a chip stacked body 200 (stacked semiconductor element). The semiconductor chips 20 are bonded to each other through an adhesive layer 601. The adhesive layer 601 is also provided on the upper surface of the chip stack 200. Moreover, the contact bonding layer 601 is comprised with the hardened | cured material of the photosensitive resin composition of this invention. The photosensitive resin composition will be described in detail later.

  A package substrate 30 shown in FIG. 1 is a build-up substrate including a core substrate 31, an insulating layer 32, a solder resist layer 33, a wiring 34, and a conductive via 35.

  Of these, the core substrate 31 is a substrate that supports the package substrate 30 and is made of, for example, a composite material in which a glass cloth is filled with a resin material.

  The insulating layer 32 is an interlayer insulating layer that insulates between the wirings 34 and between the wirings 34 and the conductive vias 35, and is made of, for example, a resin material. The solder resist layer 33 is a surface protective layer that protects the wiring formed on the outermost surface of the package substrate 30, and is made of, for example, a resin material.

  The wiring 34 and the conductive via 35 are each an electric signal transmission path, and are made of, for example, a metal material such as a simple substance or an alloy of Au, Ag, Cu, Al, and Ni.

  The solder ball 80 is electrically connected to the wiring 34, and functions as an electrode for connecting the wiring 34 to another electric circuit by being fused to an external electric circuit.

  A chip stack 200 formed by stacking a plurality of semiconductor chips 20 is placed on the upper surface of the package substrate 30. The chip stack 200 and the package substrate 30 are bonded by an adhesive layer 101.

  A part of the wiring 34 of the package substrate 30 is exposed on the upper surface of the package substrate 30, and the exposed portion and the electrode portion of each semiconductor chip 20 are connected by a bonding wire 70.

  The mold unit 50 shown in FIG. 1 is configured to cover the entire top surface of the package substrate 30 while covering the side surface and top surface of the chip stack 200. Thereby, the chip laminated body 200 can be protected from the external environment. Such a mold part 50 is comprised with various resin materials, such as an epoxy resin and a phenol resin, for example.

<Photosensitive resin composition>
Next, the photosensitive resin composition of the present invention will be described.

≪Composition≫
The photosensitive resin composition has (A) a functional group (X
) In at least one structural unit (hereinafter, simply referred to as (A) alkali-soluble resin), (B) a photoacid generator, (C) a thermal crosslinking agent, and (D) An alkoxysilane compound.

  Hereinafter, each material which comprises the photosensitive resin composition is demonstrated in detail.

<(A) Alkali-soluble resin>
(A) The alkali-soluble resin is a material that becomes a base material of the adhesive layer 601. Moreover, the photosensitive resin composition can improve the adhesive force (adhesion force) with respect to the semiconductor chip 20 of the contact bonding layer 601 by including (A) alkali-soluble resin. Therefore, the semiconductor chips 20 can be more firmly bonded to each other by the adhesive layer 601. Furthermore, since (A) the alkali-soluble resin is included, the coating film 601a becomes soluble in an alkali developer, so that it is possible to reduce the environmental load in the development process.

  Specific examples of the (A) alkali-soluble resin include cyclic olefin-based resins, phenol-based resins, acrylic resins, polyamide-based resins, and the like, and one or more of these are used in combination. be able to. Among these, a cyclic olefin resin is particularly preferable. Examples of the cyclic olefin-based resin include norbornene-based resins and benzocyclobutene-based resins. Among these, norbornene-based resins are preferable. By using a photosensitive resin composition containing a cyclic olefin-based resin, it is possible to obtain an adhesive layer 601 that is particularly excellent in adhesion to the semiconductor chip 20. In particular, the adhesive force of the adhesive layer 601 to the semiconductor chip 20 can be further increased by using a photosensitive resin composition containing a norbornene resin. In addition, since the norbornene-based resin has high hydrophobicity, the adhesive layer 601 that hardly causes dimensional change due to water absorption can be formed by using a photosensitive resin composition containing the norbornene-based resin.

  Moreover, when (A) alkali-soluble resin is cyclic olefin resin, it is preferable that cyclic olefin resin has at least one repeating unit (1st repeating unit) which has an acidic group. This acidic group is a functional group that exhibits Bronsted acidity due to (A) proton dissociation in the present invention, and the (D) alkoxysilane compound described later has a functional group that is reactive with this. For this reason, the photosensitive resin composition according to the present invention is considered to have good adhesion to a substrate such as a silicon wafer.

  The first repeating unit is a structure in which a substituent having an acidic group is bonded to a structure derived from a cyclic olefin (cyclic olefin monomer) as a main skeleton.

  Examples of structures derived from cyclic olefins include cyclohexene and cyclooctene monocyclic, norbornene, norbornadiene, dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene, tricyclopentadiene, dihydrotricyclopentadiene, tetracyclopentadiene, Examples include structures derived from polycyclic compounds such as dihydrotetracyclopentadiene. Among these, a structure derived from norbornene is particularly preferable. With the structure derived from norbornene, the adhesive force of the adhesive layer 601 to the semiconductor chip 20 can be further increased. A photosensitive resin composition containing (A) an alkali-soluble resin having a structure derived from norbornene is preferable because it is excellent in heat resistance and also excellent in flexibility after curing.

Examples of the substituent having an acidic group include a substituent having a carboxyl group, a phenolic hydroxyl group, —C (OH) — (CF ₃ ) ₂ , —N (H) —S (O) ₂ —CF _{3, and the} like. Among these, a substituent having any of a carboxyl group and —C (OH) — (CF ₃ ) ₂ is preferable. When cyclic olefin resin contains the substituent which has such an acidic group, the solubility with respect to the alkaline developing solution of the photosensitive resin composition can be improved. Therefore, in the manufacture of a semiconductor device, the undissolved residue of the photosensitive resin composition after development can be reduced, and the patterning property during development can be further improved.

  For this reason, the first repeating unit is particularly preferably at least one selected from the group consisting of the following formula (3) and the following formula (4). By including the first repeating unit having such a structure, the adhesiveness of the adhesive layer 601 to the semiconductor chip 20 can be further increased. Moreover, the solubility with respect to the alkaline developing solution of the photosensitive resin composition can be made higher.

  In the above formula (3) and the above formula (4), x and y are each preferably an integer of 0 or more and 10 or less, and more preferably an integer of 1 or more and 5 or less. Thereby, the adhesive layer 601 which can adhere | attach the semiconductor chips 20 more firmly can be obtained.

  The cyclic olefin-based resin may have at least one first repeating unit, but preferably has two or more different first repeating units. The above formula (3) and the above It is more preferred to have both first repeating units of formula (4). Thereby, the adhesiveness of the adhesive layer 601 to the semiconductor chip 20 can be further increased, and the solubility of the photosensitive resin composition in the alkaline developer can be further increased.

  The content of the first repeating unit in the cyclic olefin-based resin can be determined in consideration of the solubility of the photosensitive resin composition in an alkaline developer, and is, for example, 10 to 80 mol%. Is preferable, and it is more preferable that it is 20-70 mol%. When the content of the first repeating unit is less than the lower limit, it may be difficult to sufficiently develop solubility in an alkaline developer. If the content of the first repeating unit exceeds the upper limit, depending on the type of the first repeating unit, the characteristics of the cyclic olefin resin other than the first repeating unit may be buried. There is.

  The acidic group in the cyclic olefin resin is preferably 0.001 to 0.01 mol per 1 g of the polymer. More preferably, it is 0.0015 to 0.006 mol. Thereby, especially the solubility with respect to the alkaline developing solution of the photosensitive resin composition can be improved.

  Furthermore, it is preferable that cyclic olefin resin has a 2nd repeating unit different from the 1st repeating unit mentioned above.

  The second repeating unit is a structure in which a substituent different from the substituent of the first repeating unit is bonded to the structure derived from the cyclic olefin as the main skeleton.

As the main skeleton of the second repeating unit, those mentioned in the first repeating unit can be used, and among these, in particular, from norbornene from the viewpoint of heat resistance and flexibility after curing. The structure is preferably The main skeletons of the first and second repeating units may be different from each other, but are preferably the same. In particular, the main skeletons of the first and second repeating units are preferably structures derived from norbornene. Thereby, while being able to raise the adhesive force with respect to the semiconductor chip 20 of the contact bonding layer 601, the elasticity modulus of the contact bonding layer 601 can be lowered | hung moderately. Therefore, the semiconductor chip 20 can be more firmly bonded to each other by the adhesive layer 601, and the stress concentration generated at the bonding interface between the semiconductor chips 20 can be reduced by appropriately increasing the flexibility of the adhesive layer 601. Can do.

  As a substituent which a 2nd repeating unit has, it is preferable that it is C2-C30, and it is more preferable that it is a C4-C15 linear substituent. When the carbon number is within the above range, the elastic modulus after curing of the photosensitive resin composition can be reduced, and the flexibility of the adhesive layer 601 can be increased. Therefore, the adhesive layer 601 can further suppress cracks generated in the semiconductor chip 20 and the adhesive layer 601 due to stress concentration at the bonding interface between the semiconductor chips 20 and peeling between the semiconductor chip 20 and the adhesive layer 601. In addition, it is possible to suppress the occurrence of damage to the semiconductor chip 20 and the adhesive layer 601 due to external impact.

  The second repeating unit may be a cyclic structure, a branched structure, or the like, but is preferably a linear structure. Thereby, the elasticity modulus after hardening of the photosensitive resin composition can be lowered | hung more, and the softness | flexibility of the contact bonding layer 601 can be raised more.

  Examples of the linear substituent having 2 to 30 carbon atoms include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, and a group having an alkyl ether structure. It is preferable that it is group which has. Thereby, the photosensitive resin composition becomes more excellent in flexibility after curing.

  The group having an alkyl ether structure is particularly preferably a group represented by the following formula (5). Thereby, the softness | flexibility of the contact bonding layer 601 can be improved more.

  In the above formula (5), z is preferably an integer of 1 or more and 10 or less, and more preferably an integer of 2 or more and 6 or less. Thereby, the flexibility of the adhesive layer 601 can be further improved.

  For this reason, the second repeating unit is particularly preferably the following formula (6). (A) In addition to the first repeating unit described above, the alkali-soluble resin has a second repeating unit represented by the following formula (6), so that the solubility of the first repeating unit in an alkaline developer is sufficiently obtained. It is possible to favorably achieve both a function capable of increasing and a function of making the elastic modulus after curing of the photosensitive resin composition by the second repeating unit appropriate.

  In particular, in the above formula (6), z is preferably an integer of 1 to 10, more preferably an integer of 2 to 5. Thereby, the elasticity modulus after hardening of the photosensitive resin composition can be made more suitable.

  Moreover, when cyclic olefin resin contains a 2nd repeating unit, it is preferable that the content rate of the 2nd repeating unit in cyclic olefin resin is 20-60 mol%, for example, and it is 25-50 mol%. Is more preferable. When the content of the second repeating unit is less than the lower limit, depending on the type of the second repeating unit, it is difficult to adjust the elastic modulus after curing of the photosensitive resin composition to a desired value. There is. Further, when the content of the second repeating unit exceeds the upper limit, depending on the type of the second repeating unit, the characteristics of the cyclic olefin resin other than the second repeating unit are buried. There is a risk that.

  From the above, as the cyclic olefin-based resin, those represented by the following formula (7) are suitable. By including the cyclic olefin resin represented by the formula (7), the photosensitive resin composition has more appropriate flexibility (stress relaxation) while providing the mechanical strength necessary for the adhesive layer 601. . Further, it is possible to obtain an adhesive layer 601 that exhibits particularly excellent solubility in an alkali developer and, in addition, has particularly excellent adhesive strength to the semiconductor chip 20.

  In the above formula (7), l, m, and n are integers of 1 or more. As described above, x is preferably an integer of 0 or more and 10 or less, y is preferably an integer of 0 or more and 10 or less, and z is an integer of 1 or more and 10 or less. preferable.

  In the formula (7), the degree of polymerization of the second repeating unit relative to the degree of polymerization of the first repeating unit (that is, (l + m) / n) is preferably 0.3 to 2.0, 0 More preferably, it is 4-1.5. Thereby, it is possible to obtain a bonding layer 601 that can particularly alleviate the stress concentration generated at the bonding interface between the semiconductor chips 20 and can more firmly bond the semiconductor chips 20 to each other.

  The weight average molecular weight (Mw) of the cyclic olefin resin is preferably 5,000 to 500,000, more preferably 7,000 to 200,000, and 8,000 to 100,000. Is more preferable. Thereby, it is possible to obtain the adhesive layer 601 that is particularly excellent in the adhesive force to the semiconductor chip 20.

  In addition, the weight average molecular weight (Mw) of cyclic olefin resin can be measured using gel permeation chromatography (GPC) using cyclic olefin resin as a standard based on ASTMDS3536-91. .

The cyclic olefin resin preferably has a glass transition temperature of 100 to 250 ° C. By using a cyclic olefin resin having such a glass transition temperature, the heat resistance of the photosensitive resin composition is further increased, and the reliability of the semiconductor device 10 at a high temperature can be further increased.

  In addition, the glass transition temperature of cyclic olefin resin can be calculated | required as temperature which an exothermic reaction produces, when it heats up from normal temperature by the temperature increase rate of 5 degree-C / min, for example by the differential scanning calorimetry.

  Moreover, you may add a phenol resin as (A) alkali-soluble resin. In this case, the phenol resin is preferably a phenol novolak, a cresol novolak, a phenol aralkyl, or a biphenyl aralkyl type.

<(B) Photoacid generator>
(B) A photo-acid generator has a function which produces | generates an acid by the photoreaction at the time of exposure by energy ray irradiation, and increases the solubility with respect to an alkali developing solution. Thereby, in manufacture of a semiconductor device, it is possible to further reduce the occurrence of undissolved residue after development in an exposed portion that is an exposed portion of the photosensitive resin composition (coating film 601a). For this reason, the patterning property at the time of development can be improved. In addition, the photosensitive resin composition contains (B) a photoacid generator, so that, in the manufacture of a semiconductor device, (C) a reaction that crosslinks (A) an alkali-soluble resin with an epoxy compound (C) described later by irradiation with energy rays. Can be promoted.

  (B) Specific examples of the photoacid generator include onium salts, halogenated organic compounds, quinonediazide compounds, α, α-bis (sulfonyl) diazomethane compounds, α-carbonyl-α-sulfonyl-diazomethane compounds. , Sulfone compounds, organic acid ester compounds, organic acid amide compounds, organic acid imide compounds, and the like, and one or more of these can be used in combination. Among these, those having a quinonediazide compound are particularly preferable. Examples of the quinonediazide compound include a compound having a 1,2-benzoquinonediazide or a 1,2-naphthoquinonediazide structure. More specifically, it preferably contains 1,2-naphthoquinone-2-diazide-5-sulfonic acid or an ester compound of 1,2-naphthoquinone-2-diazide-4-sulfonic acid and a phenol compound. Since these generate a carboxyl group by a photoreaction at the time of exposure by energy ray irradiation (particularly, radiation irradiation), it is possible to further increase the solubility of an exposed portion in an alkaline developer. For this reason, the photosensitive resin composition can exhibit higher solubility in an alkali developer even at a particularly small exposure amount. As a result, the patterning property during development can be further improved.

  (B) Content of a photo-acid generator is although it does not specifically limit, It is preferable that it is 1-50 mass parts with respect to 100 mass parts of (A) alkali-soluble resin, and it is 5-30 mass parts more. preferable. When the content of the (B) photoacid generator is less than the lower limit, depending on the type of the (B) photoacid generator, the exposure and development characteristics of the photosensitive resin composition may be deteriorated. Further, even if the content of the (B) photoacid generator exceeds the above upper limit, no further increase in the effect can be expected, and depending on the type of the (B) photoacid generator, in the photosensitive resin composition (B) The characteristics of materials other than the photoacid generator may be buried.

<(C) Thermal crosslinking agent>
(C) The thermal crosslinking agent has a function of crosslinking (A) an alkali-soluble resin (particularly, a cyclic olefin-based resin).

Specific examples of the (C) thermal crosslinking agent include amine compounds, epoxy compounds, methylol compounds, and oxetane compounds, and one or more of these can be used in combination. Among these, an epoxy compound is particularly preferable. Moreover, it may be either an aromatic epoxy compound containing an aromatic ring in the molecule or an aliphatic epoxy compound not containing an aromatic ring in the molecule, but an aliphatic epoxy compound is more preferable. Thereby, the crosslinking density of (A) alkali-soluble resin in the photosensitive resin composition can be lowered | hung moderately, and the softness | flexibility of the contact bonding layer 601 can be raised moderately.

  Further, (C) the thermal crosslinking agent preferably has a branched structure or a linear structure, and more preferably has a branched structure. When the photosensitive resin composition includes a branched structure (C) and a thermal crosslinking agent, the crosslinking density of the alkali-soluble resin (A) in the photosensitive resin composition can be appropriately reduced, and the adhesive layer 601 The flexibility can be increased moderately. Thereby, the adhesive layer 601 is excellent in stress relaxation property that relaxes the stress concentration generated at the bonding interface between the semiconductor chips 20 while having the necessary mechanical strength.

  The (C) thermal crosslinking agent is preferably a compound containing two or more glycidyl groups in the molecule, more preferably a compound containing three or more and nine or less glycidyl groups in the molecule. preferable. Thereby, the crosslinking density of (A) alkali-soluble resin in the photosensitive resin composition can be lowered | hung moderately, and the adhesive layer 601 excellent in stress relaxation property can be obtained, having required mechanical strength.

Examples of such (C) thermal crosslinking agent include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl. Ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, EXA-830CRP, EXA-830VLP, EXA-835LV, EXA-850CRP (manufactured by DIC Corporation), YD-8125G, YDF-8170G, ZX-1059, ZX-1542
(Manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), YL980, YL7410, YX7700, YED216D (manufactured by Mitsubishi Chemical Corporation), EP-3300S, EP-3950L, EP-4000L, EP-4010L, EP-4088L (manufactured by ADEKA Corporation) Of these, one or a combination of two or more can be used. Among these, trimethylolpropane triglycidyl ether is particularly preferable. Thereby, the crosslinking reaction of the (A) alkali-soluble resin in the photosensitive resin composition can be promoted, and the adhesive layer 601 superior in stress relaxation property can be obtained more easily and more reliably.

  (C) Although content of a thermal crosslinking agent is not specifically limited, It is preferable that it is 1-100 mass parts with respect to 100 mass parts of (A) alkali-soluble resin, and it is more preferable that it is 5-50 mass parts. . When the content of (C) the thermal crosslinking agent is less than the lower limit value, the stress relaxation property of the adhesive layer 601 may be lowered depending on the type of (C) the thermal crosslinking agent. On the other hand, when the content of the thermal crosslinking agent (C) exceeds the upper limit, the viscosity of the photosensitive resin composition may be excessively high.

<(D) alkoxysilane compound>
By including the (D) alkoxysilane compound, the photosensitive resin composition suppresses the coating film 601a from being peeled from the wafer 201 when the wafer 201 provided with the coating film 601a is patterned by exposure and development, for example. I can do it. Thus, by increasing the adhesion between the coating film 601a and the wafer 201, a highly reliable chip stack 200 can be finally obtained.

  The (D) alkoxysilane compound preferably contains an aromatic ring. Thereby, by improving compatibility with resin, it can suppress that the residue of the coating film melt | dissolved in the developing solution remains in the opening part of a pattern at the time of alkali image development, and patterning property improves.

Further, the (D) alkoxysilane compound preferably includes a functional group that reacts with a functional group that exhibits Bronsted acidity by proton dissociation of the (A) alkali-soluble resin. Thereby, the adhesiveness with the wafer 201 improves by forming a crosslinked structure between (D) alkoxysilane compound and (A) alkali-soluble resin.
Here, in the (D) alkoxysilane compound, it is preferable that the functional group that reacts with the functional group that exhibits Bronsted acidity by proton dissociation of the (A) alkali-soluble resin is directly bonded to the aromatic ring. Thereby, the improvement of the patterning property at the time of alkali development and the improvement of the adhesiveness with the wafer 201 can be made compatible.

As such (D) alkoxysilane compound, a compound having a chemical structure represented by the following general formula (1) is preferably used, and a functional group exhibiting reactivity with a functional group exhibiting Bronsted acidity by proton dissociation. R ₁ is directly bonded to the aromatic ring, an alkylene group R ₂ having 1 to 10 carbon atoms is bonded to the functional group R ₁ , and a 0-trivalent alkoxysilyl group is bonded to the alkylene group R _2. Are connected.

In the above general formula (1), X is a carbon atom or nitrogen atom, R ₁ is a functional group showing reactivity with a functional group showing Bronsted acidity by proton dissociation, R ₂ is an alkylene group having 1 to 10 carbon atoms, R ₃ and R ₄ represent an alkyl group having 1 to 3 carbon atoms, and t represents 0 to 3.
Since the functional group R ₁ of the alkoxysilane compound having the chemical structure of the general formula (1) has good reactivity with the (A) alkali-soluble resin, the photosensitive resin composition according to the present invention is It is considered that the adhesiveness is improved.
Here, the functional group R ₁ is not particularly limited as long as it is a functional group that is reactive with a functional group that exhibits Bronsted acidity by proton dissociation, but includes, for example, secondary amine, tertiary amine, urethane, ureido, and the like. A nitrogen functional group is preferable, and among these, a secondary amine or a tertiary amine is particularly preferable.
In addition, as the (D) alkoxysilane compound, it is also preferable to use a compound having a chemical structure represented by the following general formula (2), and a functional group R showing reactivity with a functional group showing Bronsted acidity by proton dissociation. ₁ is directly bonded to the aromatic ring, and an alkylene group R ₂ having 1 to 10 carbon atoms is bonded to the aromatic ring separately from the functional group R _1, and 0 to 3 is bonded to the alkylene group R ₂ . A valent alkoxysilyl group is bonded.

In the above general formula (2), X is a carbon atom or a nitrogen atom, R ₁ is a functional group showing reactivity with a functional group showing Bronsted acidity by proton dissociation, R ₂ is an alkylene group having 1 to 10 carbon atoms, R ₃ and R ₄ represent an alkyl group having 1 to 3 carbon atoms, and t represents 0 to 3.
The functional group R ₁ of the alkoxysilane compound having the chemical structure of the general formula (2) has a good reactivity with the (A) alkali-soluble resin, and the photosensitive resin composition according to the present invention has the wafer 20
It is considered that the adhesiveness with 1 is improved.
Here, the functional group R ₁ is not particularly limited as long as it is reactive with a functional group that exhibits Bronsted acidity by proton dissociation. For example, primary amine, secondary amine, tertiary amine, ureido, etc. Of these, a nitrogen-containing functional group, a hydroxyl group, a thiohydroxyl group, and a glycidoxy group are preferable, and among these, a secondary amine or a glycidoxy group is more preferable.
Is cited two examples in the form of (D) an alkoxysilane compound in the present invention, both the functional groups R ₁ showing reactivity with the functional group showing a Bronsted acid by proton dissociation is directly bonded to an aromatic ring Is common, and there is some action between the aromatic ring and the functional group R ₁ , and it is presumed that the synergistic effect contributes to the improvement of adhesiveness.
(D) More specifically, examples of the alkoxysilane compound include 3- (2-glycidoxyphenyl) propyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and 3- (4-aminophenyl). Propyltrimethoxysilane, 3- (4-aminophenyl) propyltrimethoxysilane, 3- (N-methyl-N- (4-pyridyl) amino) propyltrimethoxysilane, 3- (3-phenylureido) propyltriethoxy Examples include silane. Thereby, the adhesiveness of the coating film 201a and the wafer 201 can be improved more. Of these, 3- (2-glycidoxyphenyl) propyltrimethoxysilane and N-phenyl-3-aminopropyltrimethoxysilane are particularly preferable. In the former, an oxygen atom is bonded to the benzene ring, and in the latter, a nitrogen atom is bonded to the benzene ring, both of which have an unshared electron pair that can be conjugated with the π electron of the benzene ring. The presence of this unshared electron pair contributes to the synergistic effect described above, and as a result, may contribute to the improvement of adhesion.

  (D) It is preferable that it is 0.1-30 mass parts with respect to 100 mass parts of (A) alkali-soluble resin, and, as for content of an alkoxysilane compound, it is more preferable that it is 0.2-20 mass parts. (D) When the content of the alkoxysilane compound is less than the lower limit, peeling may occur between the coating 201a and the wafer 201 when patterning is performed by alkali development. (D) Even if the content of the alkoxysilane compound exceeds the upper limit, no further increase in effect can be expected. (D) Depending on the type of the alkoxysilane compound, the adhesion between the adhesive layer 601 and the chip 20 may be increased. There is a risk of exacerbating it significantly.

The photosensitive resin composition may further contain one or more adhesion assistants in addition to the above (D) alkoxysilane compound. Specifically, for example, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 5, 6-epoxyhexyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxy Silane, 3-acryloxypropyltrimethoxysilane, bis [3- (triethoxysilyl) propyl] tetrasulfide, bis [3- (triethoxysilyl) propyl] disulfide, 3-isocyanatopropyltrie Xysilane, phenyltrimethoxysilane, phenyltriethoxysilane, benzoyloxypropyltrimethoxysilane, benzoyloxypropyltriethoxysilane, 1,6-bis (trimethoxysilyl) hexane, norbornenyltrimethoxysilane, norbornenyl Triethoxysilane, 3- (triethoxysilyl) propyl succinic anhydride, 6-azidosulfonylhexyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ) Ethyltriethoxysilane, tris (3-trimethoxysilylpropyl) isocyanurate, [2- (3-cyclohexenyl) ethyl] trimethoxysilane, [2- (3-cyclohexenyl) ethyl] triethoxysilane, 3-cyclopentadienylpropyl) triethoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, Decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, bis (triethoxysilyl) methane, bis (trimethoxysilyl) ethane, bis (triethoxysilyl) ethane, bis (trimethoxysilyl) Hexane, bis (triethoxysilyl) hexane, bis (trimethoxysilyl) octane, bis (triethoxysilyl) octane, bis (trimethoxysilyl) benzene, bis [(3-methyldimethoxysilyl) propyl [Lopyl] polypropylene oxide, polymethacrylic acid trimethoxysilyl ester, polymethacrylic acid triethoxysilyl ester, trifluoropropyltrimethoxysilane, 1,3-dimethyltetramethoxydisiloxane, and the like. It is not limited to these. These may be used alone or in admixture of two or more. Thereby, the adhesiveness of the photosensitive resin composition (adhesion layer 601) can be improved more.

  Even when these adhesion assistants are included, the content of the (D) alkoxysilane compound is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble resin. It is more preferable that it is 2-20 mass parts. (D) When the content of the alkoxysilane compound is less than the lower limit, peeling may occur between the coating 201a and the wafer 201 when patterning is performed by alkali development. (D) Even if the content of the alkoxysilane compound exceeds the upper limit, no further increase in effect can be expected. (D) Depending on the type of the alkoxysilane compound, the adhesion between the adhesive layer 601 and the chip 20 may be increased. There is a risk of exacerbating it significantly.

  The photosensitive resin composition contains (A) an alkali-soluble resin, (B) a photoacid generator, (C) a thermal crosslinking agent, and (D) an alkoxysilane compound as described above. In manufacturing, for example, when the coating film 601a applied on the wafer 201 is patterned or when the semiconductor chips 20 are pressure-bonded via the adhesive layer 601, the coating film 601a, the wafer 201, the adhesive layer 601 and the semiconductor Separation from the chip 20 is less likely to occur. Therefore, a highly reliable chip stack 200 can be obtained. Moreover, although the adhesive layer 601 has a single-layer structure, it has stress relaxation properties in addition to sufficient adhesiveness. For this reason, it is not necessary to provide two layers of the layer excellent in adhesiveness and the layer excellent in stress relaxation between the semiconductor chips 20, Therefore, the whole thickness of the chip laminated body 200 is remarkably thick. Can be avoided. As a result, it is possible to obtain a highly reliable semiconductor device 10 having a low profile and excellent adhesion and stress relaxation properties. Such a semiconductor device 10 has a very small internal volume, such as a mobile device, and is particularly useful in an electronic device that is used while being carried. That is, it is useful in that it contributes to the reduction in size, thickness, and weight of the electronic device and that the function of the semiconductor device 10 is hardly impaired even when the electronic device is dropped or swung.

  Moreover, the photosensitive resin composition may further contain a phenol compound, a leveling agent, a flame retardant, a plasticizer, a curing accelerator, an antioxidant, and the like as necessary.

Examples of the phenol compound include 4-ethylresorcinol, 2-propylresorcinol, 4-butylresorcinol, 4-hexylresorcinol, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 4,4 '-Dihydroxydiphenyl sulfide, 3,3'-dihydroxydiphenyl disulfide, 4,4'-dihydroxydiphenyl sulfone, 2,2'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenylmethane, 2,2'-dihydroxydiphenyl ether, 4, 4'-dihydroxydiphenyl ether, 4,4 '-(1,3-dimethylbutylidene) diphenol, 4,4'-(2-ethylhexylidene) diphenol, 4,4'-ethylidenebisphenol, 2,2 '-Ethylenedioxydiphenol 3,3′-ethylenedioxydiphenol, 1,5-bis (o-hydroxyphenoxy) -3-oxapentane, diphenoic acid, Bis-Z (made by Honshu Chemical Industry Co., Ltd.), Ph-RS-Z (Honshu) Chemical Industries, Ltd.), 4- (1,1-dimethylpropyl) phenol, 4-cyclohexylphenol, 4- (1,1,3,3-tetramethylbutyl) phenol, 4- (4-hydroxyphenyl)- 2-butanone, 4′-hydroxybutyrophenone, 4′-hydroxyvalerophenone, 4′-hydroxyhexanophenone, 3- (4-hydroxyphenyl) propionic acid, methyl 3-hydroxybenzoate, ethyl 3-hydroxybenzoate, Methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, 4 Isopropyl hydroxybenzoate, butyl 4-hydroxybenzoate, isobutyl 4-hydroxybenzoate, hexyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, 1,3-bis [2- (4-hydroxyphenyl) -2- Propyl] benzene, BisP-DED (manufactured by Honshu Chemical Industry Co., Ltd.), and the like. Among these, one kind or two or more kinds can be used in combination.

  By including such a phenol compound, solubility in an alkali developer and an organic solvent can be enhanced.

  Examples of the antioxidant include phenolic antioxidants, amine antioxidants, phosphorus antioxidants, and thioether antioxidants. Of these, one or a combination of two or more may be used. Among these, it is preferable to use a combination of a phenolic antioxidant and an amine antioxidant.

  By including such an antioxidant, oxidation during curing of the photosensitive resin composition and oxidation of the photosensitive resin composition (coating film 601a) in the subsequent process or the like can be suppressed.

Examples of phenolic antioxidants include pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 3,9-bis {2- [3- (3-t -Butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} 2,4,8,10-tetraoxaspiro [5,5] undecane, octadecyl-3- (3,5- Di-t-butyl-4-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl -2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 2,6-di-t-butyl-4-methylphenol, 2,6-di- -Butyl-4-ethylphenol, 2,6-diphenyl-4-octadecyloxyphenol, 2,6-bis [(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol, stearyl (3,5 -Di-t-butyl-4-hydroxyphenyl) propionate, distearyl (3,5-di-t-butyl-4-hydroxybenzyl) phosphonate, thiodiethylene glycol bis [(3,5-di-t-butyl-4 -Hydroxyphenyl) propionate], 4,4'-thiobis (6-tert-butyl-m-cresol), 2-octylthio-4,6-di (3,5-di-tert-butyl-4-hydroxyphenoxy) -S-triazine, 2,2'-methylenebis (4-methyl-6-tert-butyl-6-butylphenol), 2,2'-methylenebis 4-ethyl-6-tert-butylphenol), bis [3,3-bis (4-hydroxy-3-tert-butylphenyl) butyric acid] glycol ester, 4,4′-butylidenebis (6-tert-butyl-m-) Cresol), 2,2'-ethylidenebis (4,6-di-t-butylphenol), 2,2'-ethylidenebis (4-s-butyl-6-t-butylphenol), 1,1,3-tris (2-Methyl-4-hydroxy-5-t-butylphenyl) butane, bis [2-t-butyl-4-methyl-6- (2-hydroxy-3-t-butyl-5-methylbenzyl) phenyl] Terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-di-tert-butyl-4- Hydroxy Benzyl) -2,4,6-trimethylbenzene, 1,3,5-tris [(3,5-di-t-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, tetrakis [methylene-3- ( 3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 2-tert-butyl-4-methyl-6- (2-acryloyloxy-3-tert-butyl-5-methylbenzyl) phenol, 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane-bis [β- (3-t-butyl-4-hydroxy -5-methylphenyl) propionate], triethylene glycol bis [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate], 1, 1′-bis (4-hydroxyphenyl) cyclohexane, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 2, 2′-methylenebis (6- (1-methylcyclohexyl) -4-methylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis (2- (3-t -Butyl-4-hydroxy-5-methylphenylpropionyloxy) 1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, 4,4'-thiobis (
3-methyl-6-tert-butylphenol), 4,4′-bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, 4,4′-thiobis (6-tert-butyl-2-) Methylphenol), 2,5-di-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2,4-dimethyl-6- (1-methylcyclohexyl, styrenated phenol, 2,4-bis ((octylthio) methyl) -5-methylphenol, and the like. Phenol antioxidants such as 2,6-bis [(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol are preferred.

Examples of amine-based antioxidants include N, N′-di-sec-butyl-p-phenylenediamine, 4,4′-dimethoxydiphenylamine, 4-isopoloxydiphenylamine, N-isopropyl-N′-phenyl-p-phenylene. Examples include diamine, N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine, 4,4′-di (α, α-dimethylbenzyl) diphenylamine, and among these, 4,4 Diphenylamine compounds such as' -dimethoxydiphenylamine, 4-isopoloxydiphenylamine, and 4,4'-di (α, α-dimethylbenzyl) diphenylamine are preferred.

  Phosphorus antioxidants include bis- (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, tris (2,4-di-t-butylphenylphosphite), tetrakis ( 2,4-di-t-butyl-5-methylphenyl) -4,4'-biphenylenediphosphonite, 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, bis- (2, 6-Dicumylphenyl) pentaerythritol diphosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, Tris (mixed mono and di-nonylphenyl phosphite), bis (2 , 4-Di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methoxy) Carbonyl-ethyl - phenyl) pentaerythritol diphosphite, bis (2,6-di -t- butyl-4-octadecyloxycarbonyl ethyl - phenyl) pentaerythritol diphosphite and the like. Of these, phosphites and phosphates are preferred.

Examples of the thioether-based antioxidant include dilauryl-3,3′-thiodipropionate, bis (2-methyl-4- (3-n-dodecyl) thiopropionyloxy) -5-t-butylphenyl) sulfide, Examples include stearyl-3,3′-thiodipropionate and pentaerythritol-tetrakis (3-lauryl) thiopropionate.

  When the photosensitive resin composition contains an antioxidant, the content of the antioxidant is preferably 0.1 to 50 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble resin, 0.5 to More preferably, it is 30 parts by mass.

≪Physical properties≫
Next, physical properties of the photosensitive resin composition (physical properties of the adhesive layer 601) will be described in detail.

  The cured product of the photosensitive resin composition, that is, the elastic modulus of the adhesive layer 601 is preferably 2.0 to 3.5 GPa at 25 ° C. Moreover, it is preferable that the elasticity modulus of the state before hardening of the photosensitive resin composition is 70 to 120% of the elasticity modulus in 25 degreeC of 25 degreeC of hardened | cured material. Moreover, it is preferable that the adhesive force with respect to the semiconductor chip 20 of the photosensitive resin composition in the state before the hardening used for the etching process and the ashing process is 20.0-200.0N at 25 degreeC.

  Such a photosensitive resin composition has an elastic modulus in a state before curing within a predetermined range with respect to the elastic modulus after curing, for example, the photosensitive resin composition before curing is significantly deformed. The risk of running out is reduced. For this reason, it is possible to improve the alignment accuracy when the semiconductor chips 20 are stacked. Furthermore, since the amount of change in elastic modulus before and after curing is relatively small, the amount of shrinkage associated with photosensitivity can also be reduced, and the stress generated at the interface with the semiconductor chip 20 due to curing shrinkage can be reduced. it can. From this viewpoint, it contributes to improving the reliability of the chip stack 200.

  On the other hand, the photosensitive resin composition in a state before being subjected to the etching process and the ashing process has a sufficient adhesion force required for die bonding to the semiconductor chip 20. For this reason, the adhesive layer 601 that bonds the semiconductor chips 20 to each other more firmly fixes the semiconductor chips 20 to each other and contributes to improving the reliability of the chip stack 200.

  According to the photosensitive resin composition that satisfies the above conditions, it is easier to realize the adhesive layer 601 that has both sufficient adhesiveness and stress relaxation properties. In other words, since the adhesive layer 601 combines the element protection function (buffer coating function) of the buffer coating film and the bonding function (die bonding function) of the die bonding film with one layer, the reliability is lowered. It is possible to form the chip stacked body 200 without reducing the thickness of the chip stacked body 200 as compared with the conventional structure using two layers. Further, as the chip stack 200 is made thinner, the volume of the mold part 50 can be reduced and the bonding wire 70 can be shortened, thereby contributing to weight reduction and cost reduction.

  Further, the elastic modulus (25 ° C.) of the cured product of the photosensitive resin composition is more preferably 2.2 to 3.2 GPa, and further preferably 2.4 to 3.0 GPa. In addition, when the elasticity modulus of hardened | cured material is less than the said lower limit, depending on the composition of the photosensitive resin composition, the adhesive force of the contact bonding layer 601 falls a little, or when the filler is contained in the mold part 50. The filler may penetrate the adhesive layer 601 and adversely affect the semiconductor chip 20. On the other hand, when the elastic modulus of the cured product exceeds the upper limit value, depending on the composition of the photosensitive resin composition, the flexibility of the adhesive layer 601 is reduced, so that the stress relaxation property is reduced. Residual stress generated along with this and local concentration of thermal stress due to the difference in thermal expansion between the semiconductor chip 20 and the adhesive layer 601 cannot be alleviated, and the semiconductor chip 20 may be cracked.

  The elastic modulus of the cured product is, for example, an ultra-micro hardness meter ENT-1000 (manufactured by Elionix Co., Ltd.) with a measurement temperature of 25 ° C., a load of 2 mN, a holding time of 1 second, and a Berkovich indenter (triangular pyramid, It can be obtained by measuring in accordance with ISO14577 using the opposite ridge angle (115 °).

  Moreover, the elasticity modulus of the hardened | cured material of the photosensitive resin composition can be calculated | required as an elasticity modulus of the coating film 601a after a mounting process.

  The elastic modulus (25 ° C.) of the photosensitive resin composition before curing is more preferably 75 to 115% of the elastic modulus at 25 ° C. of the cured product, and further preferably 80 to 110%. . In addition, when the elasticity modulus in the state before hardening is less than the lower limit value, although the adhesiveness increases, the film of the photosensitive resin composition is likely to be deformed. For example, the semiconductor chip 20 is temporarily disposed through the film. At that time, the position may be easily displaced, or the photosensitive resin composition may flow out. On the other hand, when the elasticity modulus in the state before hardening exceeds the said upper limit, adhesiveness falls and there exists a possibility that it may become difficult to arrange | position the semiconductor chip 20 temporarily.

  In addition, the elasticity modulus of the state before hardening can be measured similarly to the elasticity modulus of hardened | cured material.

  Moreover, the elasticity modulus of the state before hardening of the photosensitive resin composition can be calculated | required as an elasticity modulus of the coating film 601a after a process process and before a mounting process.

  On the other hand, the adhesive force (25 ° C.) of the photosensitive resin composition to the semiconductor chip 20 in a state before being subjected to etching treatment and ashing treatment is more preferably 30 to 180 N, further preferably 40 to 160 N. Is done. Note that when the adhesive force is lower than the lower limit, bubbles may easily enter the interface between the adhesive layer 601 and the semiconductor chip 20. On the other hand, if the adhesive force exceeds the upper limit, if bubbles enter the interface between the adhesive layer 601 and the semiconductor chip 20, it may be difficult to remove.

  In addition, the adhesive force with respect to the semiconductor chip 20 is obtained by bonding the semiconductor chips 20 to each other through the photosensitive resin composition of the present invention in a state before being subjected to the etching process and the ashing process, and then the chip stack 200. Using a universal bond tester Dage 4000 (manufactured by Daisy Japan Co., Ltd.), the semiconductor chip is pushed horizontally (in the in-plane direction of the semiconductor chip 20) with the share tool from the side (side surface) of the semiconductor chip 20, and between the semiconductor chips 20 It is calculated | required as intensity | strength (die shear strength) when the joint surface of this is fractured.

  In addition, the adhesive strength of the photosensitive resin composition to the semiconductor chip 20 in the state before being subjected to the etching treatment and the ashing treatment is the coating film 601a after the treatment step after the etching treatment and the ashing treatment and before the mounting step. It can be determined as an adhesive force to the semiconductor chip 20.

The etching process is, for example, a process of removing a passivation film on the surface of the semiconductor chip 20 and exposing a pad for connecting the bonding wire 70, and specifically, a fluorine compound gas (CF) as a gas. ₄ ) Using a mixed gas of argon gas (Ar) and oxygen gas (O ₂ ), with an output of 2500 W, a time of 6 minutes, and a CF ₄ flow rate / Ar flow rate / O ₂ flow rate of 200 sccm / 200 sccm / 50 sccm. The etching process to perform is mentioned.

The ashing process is a process for removing, for example, processing residues generated by the etching process and cleaning the surface of the adhesive layer 601 and the pad surface. Specifically, oxygen gas (O ₂ ) is used. The plasma treatment is performed under the conditions that the output is 600 W, the time is 12 minutes, and the O ₂ flow rate is 200 sccm.

  In addition, since such an etching process and an ashing process may accelerate | stimulate deterioration of an organic material, when it is an adhesion layer with low etching resistance and ashing resistance, the semiconductor chips 20 cannot fully adhere | attach each other. There is a fear. On the other hand, since the adhesive layer 601 formed using the photosensitive resin composition has sufficient etching resistance and ashing resistance, even after undergoing such etching processing and ashing processing. As a result, a decrease in adhesive strength is suppressed, and as a result, the adhesive strength as described above is expressed. Therefore, since such a photosensitive resin composition does not need to consider a decrease in adhesiveness in various treatments in the adhesive process, the manufacturing process can be simplified and the cost can be easily reduced. It is useful in.

  Moreover, it is preferable that the elasticity modulus of the photosensitive resin composition has the change before and behind a process process in the fixed range. In other words, the heating conditions in the heating process that are thought to affect the resistance to the processing process (etching resistance and ashing resistance) are such that the elastic modulus of the photosensitive resin composition is within a certain range before and after the processing process. It is preferable to set appropriately so as to be within the range.

  Specifically, the elastic modulus (25 ° C.) after the heating step and before the treatment step of the photosensitive resin composition is X [GPa], and the elastic modulus (25 ° C.) after the treatment step is Y [GPa]. In this case, it is preferable to satisfy the relationship of 0.7 ≦ X / Y ≦ 1.5, and it is more preferable to satisfy the relationship of 0.8 ≦ X / Y ≦ 1.3. When the change in elastic modulus before and after the treatment process satisfies the above relationship, the coating film 601a composed of the photosensitive resin composition has sufficient mechanical properties to maintain the patterned shape, It has sufficient adhesiveness to bond the semiconductor chips 20 together. That is, since the treatment process involves an etching process or an ashing process, the coating film 601a easily deteriorates. However, when the elastic modulus satisfies the above relationship before and after the treatment process, the coating film 601a is patterned. It sufficiently functions as the adhesive layer 601 in the mounting process, while maintaining a sufficient shape. For this reason, when the change in elastic modulus before and after the treatment process satisfies the above relationship, the coating film 601a formed of such a photosensitive resin composition has a function as an etching mask and a function as an adhesive layer 601. Can be compatible.

  Note that the processing step in the above-mentioned regulation is an etching process and an ashing process that satisfy the above-described processing conditions.

  Moreover, it is preferable that the minimum melt viscosity in the range of 100-200 degreeC is 20-500 Pa.s in the state before the hardening of the photosensitive resin composition. Since such a composition is excellent in wettability with respect to the semiconductor chip 20, it becomes difficult for voids or the like to be generated in the adhesive layer 601. Accordingly, since a uniform adhesive layer 601 with little variation in physical properties can be formed, when the semiconductor chips 20 are bonded to each other via the adhesive layer 601, it is difficult to cause local concentration of stress, and cracks are generated in the semiconductor chip 20. In addition, the occurrence of peeling between the semiconductor chip 20 and the adhesive layer 601 can be further suppressed. In addition, the melt viscosity before hardening of the photosensitive resin composition can be measured with a rheometer. Moreover, the melt viscosity in the state before hardening of the photosensitive resin composition can be calculated | required as a melt viscosity of the coating film 601a after a process process and before a mounting process.

  The minimum melt viscosity before curing is more preferably 25 to 400 Pa · s, and further preferably 30 to 300 Pa · s.

  Moreover, while the photosensitive resin composition has a certain adhesiveness when it is in the state before the curing, the adhesiveness can be reduced by performing UV irradiation treatment on the photosensitive resin composition. Therefore, it can be said that this photosensitive resin composition can control the adhesiveness depending on the presence or absence of UV irradiation treatment.

  Specifically, the photosensitive resin composition is in a state before being cured, and the state after being subjected to the etching process and the ashing process described above is preferable with respect to the UV peeling type back grind film 90. Exhibits an adhesive strength of 3.0 N / 25 mm or more at 25 ° C. Such a photosensitive resin composition can exhibit a sufficient adhesive force to the back grind film 90 even after being subjected to a treatment that promotes deterioration of an organic material such as an etching treatment or an ashing treatment. Therefore, for example, when the back grinding process is performed on the wafer 201 on which the coating film 601a of the photosensitive resin composition is formed, the wafer 201 can be securely fixed, and the accuracy of the back grinding process can be further improved.

  The adhesive strength is more preferably 3.5 N / 25 mm or more and 10.0 N / 25 mm or less.

  The adhesive strength is such that a UV peeling type back grind film 90 (width 25 mm, length 75 mm) is bonded so that the adhesive surface is in contact with the coating film 601a of the photosensitive resin composition, and the measurement temperature is 25 ° C. And then pulling one end in the longitudinal direction of the back grind film 90 so that the peel angle is 180 °, with the peeling speed being 10.0 ± 0.2 mm / s, and the coating film of the photosensitive resin composition When the back grind film 90 is peeled from 601a, the average value of the load required for peeling (180 ° peel adhesive strength, unit: N / 25 mm, JIS Z 0237 compliant) can be obtained.

  On the other hand, the photosensitive resin composition is in a state before being cured and after being subjected to the UV irradiation treatment, preferably at 50 ° C. with respect to the UV peeling type back grind film 90. It exhibits an adhesive strength of 5 N / 25 mm or less. Since such a photosensitive resin composition can sufficiently reduce the adhesive strength to the back grind film 90 by UV irradiation treatment, for example, the back grind film 90 is pasted on the coating film 601a of the photosensitive resin composition. In addition, when the back grind film 90 is peeled off from the coating film 601a of the photosensitive resin composition after the back grinding treatment, the back grind film 90 can be smoothly peeled without exerting a large load on the coating film 601a. In addition, since the back grind film 90 can be peeled without impairing the adhesion between the coating film 601a and the semiconductor chip 20, for example, when picking up the pieces 21, 22 after dicing, The occurrence of defects such as chipping can be prevented.

  Further, by reducing the adhesive strength of the coating film 601a as described above, for example, the photosensitive resin composition adheres to the dicing blade 110 in the dicing process, or the photosensitive resin composition adheres to the collet 121 in the mounting process. Can be suppressed. As a result, it is possible to suppress the occurrence of dicing failure and pickup failure.

  The adhesive strength is more preferably 0.05 N / 25 mm or more and 0.40 N / 25 mm or less.

In addition, the UV irradiation process is a process of irradiating light having a wavelength of 365 nm so that the integrated light amount is 600 mJ / cm ² .

  Further, the UV peeling type back grind film 90 used in the above regulations is made of acrylic resin.

  In addition, the measurement of the adhesive force at 50 ° C. with respect to the back grind film 90 after being subjected to the UV irradiation treatment of the coating film of the photosensitive resin composition is performed after being subjected to the etching treatment and the ashing treatment described above. This can be performed in the same manner as the measurement of the adhesive strength at 25 ° C. with respect to the back grind film 90.

<Method for Manufacturing Semiconductor Device>
Next, a method for manufacturing a semiconductor device of the present invention will be described.

  2 to 5 are diagrams for explaining a method of manufacturing the semiconductor device shown in FIG. In the following description, for convenience of explanation, the upper part of FIGS. 2 to 5 is referred to as “upper” and the lower part is referred to as “lower”.

  The manufacturing method of the semiconductor device 10 includes a coating process for coating a liquid containing a photosensitive resin composition on a wafer (semiconductor substrate), an exposure process for exposing the obtained coating film, and development for patterning the coating film by development. A process, a heating process for heating the coating film, a processing process for performing etching and ashing on the wafer provided with the heated coating film, a back grinding process for grinding the back surface of the wafer, and dicing the wafer A dicing process for dividing into a plurality of semiconductor chips, and a mounting process in which a semiconductor chip is picked up and mounted on a package substrate, and then another semiconductor chip is picked up and pressure-bonded onto the previously mounted semiconductor chip. Have. Hereinafter, each process will be described sequentially.

[1] Application Step First, a wafer 201 (see FIG. 2A) for cutting out the semiconductor chip 20 is prepared, and a liquid containing the photosensitive resin composition is applied thereon (one surface side). Thereby, as shown in FIG. 2B, a coating film 601 a is formed on the wafer 201. The wafer 201 is formed with semiconductor circuits, electrode pads, and the like so as to include a plurality of semiconductor chips 20 in advance. That is, the wafer 201 is used for a so-called pre-process of the semiconductor manufacturing process. Therefore, a plurality of semiconductor chips 20 can be cut out by cutting the wafer 201 in steps described later and separating the wafer 201 into individual pieces.

  A coating method is not particularly limited, and examples thereof include a spin coating method, a spray coating method, an ink jet method, a roll coating method, and a printing method.

  If necessary, the applied liquid (liquid film) may be heated and dried. In this case, the heating temperature is preferably 70 to 160 ° C, and more preferably 80 to 150 ° C. Moreover, although heating time is suitably set according to heating temperature, it is preferable that it is 5 seconds-30 minutes, and it is more preferable that it is 10 seconds-15 minutes.

The liquid containing the photosensitive resin composition is prepared by appropriately adding a solvent or the like that dissolves the liquid to the photosensitive resin composition of the present invention. Moreover, it is preferable that the solvent to be used is a solvent that can be volatilized and removed when heated in a process described later. Specifically, toluene, xylene, benzene, dimethylformamide, tetrahydrofuran, ethyl cellosolve, ethyl acetate, N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether , Diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, methyl-1,3-butylene glycol acetate, 1,3 -Butylene glycol-3-monomethyl ether, methyl pyruvate , Ethyl pyruvate, 3-methoxy-3-methylcyclohexyl-butanol, 3-methoxybutanol, include methyl 3-methoxy propionate or the like, can be used singly or in combination of two or more of them. Among these, a solvent containing any of propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, γ-butyrolactone and cyclohexanone is preferably used because it is highly soluble and easily removed by volatilization.

[2] Exposure Step Next, an exposure process is performed on a desired region of the coating film 601a formed on the wafer 201 (see FIG. 2C). As a result, a photoreaction occurs in the coating film 601a in the exposure region, and patterning is potentially performed (latent image is formed).

  In order to perform an exposure process on a desired region of the coating film 601a, as shown in FIG. 2C, a mask 4 provided so as to be in contact with the coating film 601a can be used.

  As light used for the exposure process, electromagnetic waves and particle beams having various wavelengths are used. For example, ultraviolet rays such as i-rays, visible rays, lasers, X-rays, electron beams, and the like are used. Among these, ultraviolet rays or visible rays having a wavelength of about 200 to 700 μm are preferably used. The exposure process can be performed in, for example, an air atmosphere, an inert gas atmosphere, or a reduced pressure atmosphere.

  In this exposure step, a mask provided separately from the coating film 601a may be used instead of the mask 4 provided in contact with the coating film 601a. Note that the use of a mask can be omitted when a highly directional material such as an X-ray or an electron beam is used.

Although the exposure amount in the exposure processing is appropriately set according to the thickness of the coating film 601a, the sensitivity of the photosensitive resin composition, and the like, it is preferably about 30 to 3000 mJ / cm ² as an example.

[3] Development Step Next, the coating film 601a subjected to the exposure processing is subjected to development processing. Thereby, the coating film 601a in the exposed portion is removed, and desired patterning is performed as shown in FIG. By such development processing, for example, a pad for connecting the bonding wire 70 to the semiconductor chip 20 can be exposed, or the coating film 601a on the dicing line that is to be cut in a dicing process described later can be removed. .

  In the development process, the developer is brought into contact with the coating film 601a subjected to the exposure process. Thereby, the coating film 601a in the exposed portion is dissolved in the developer and removed. Thereby, the opening part 601b is formed in the coating film 601a. Developers include, for example, alkali metal carbonates, alkali metal hydroxides, alkali developers such as tetraammonium hydroxide, organic developers such as dimethylformamide, N-methyl-2-pyrrolidone, and the like. In particular, an alkali developer is preferably used. Alkali developers have the characteristics that the burden on the environment is small and residues are not easily generated.

  Moreover, as a supply method of a developing solution, systems, such as a spray, a paddle, immersion, and an ultrasonic wave, are mentioned, for example.

  In the present embodiment, the coating film 601a has a so-called positive-type photosensitivity, but the coating film 601a may have a so-called negative-type photosensitivity.

[4] Heating Step Next, the coating film 601a subjected to the development processing is heated (see FIG. 2 (e)). Thereby, predetermined | prescribed hardening reaction arises in the photosensitive resin composition which comprises the coating film 601a, and moderate adhesiveness expresses in the coating film 601a.

Although the heating temperature of the coating film 601a is not specifically limited, It is preferable that it is 80-170 degreeC, and it is more preferable that it is 120-160 degreeC. On the other hand, the heating time is appropriately set according to the heating temperature, but is preferably 35 to 120 minutes, and more preferably 40 to 100 minutes. As a result, mechanical properties such as the elastic modulus of the coating film 601a are optimized, and sufficient resistance to an etching process and an ashing process in a processing step described later is imparted to the coating film 601a.
The coating film 601a is formed of the photosensitive resin composition of the present invention, and the adhesive layer 601 formed from such a coating film 601a exhibits relatively high solubility in an organic solvent. Become. For this reason, for example, even when it is necessary to remove the coating film 601a after forming the coating film 601a on the wafer 201, the coating film 601a is efficiently dissolved while suppressing the generation of residues (residues). Can be removed. Thus, the wafer 201 can be used again (reworked) without wasting the wafer 201, and the process yield can be improved.

[5] Processing Step Next, an etching process is performed on the wafer 201 provided with the heated coating film 601a. Thereby, the coating film 601a provided with the opening 601b functions as an etching mask, and an etching process is selectively performed on a region corresponding to the opening 601b in the surface (upper surface) of the wafer 201. As a result, when a passivation film is formed on the surface of the wafer 201, it can be removed and a pad for connecting the bonding wire 70 can be exposed.

Examples of the etching process include plasma etching (dry etching) in which etching is performed by supplying plasma as shown in FIG. 3 (f), various wet etching processes, and the like. Among these, the plasma etching treatment can be performed under generally known conditions. For example, fluorine compound gas (CF ₄ , CHF ₃ ), fluorine compound gas (CF ₄ , CHF ₃ ) and oxygen Using gas mixture with gas (O ₂ ), mixture gas of fluorine compound gas (CF ₄ , CHF ₃ ) and argon gas (Ar), output is 200 to 2000 W, time is 0.2 to 15 minutes, gas flow rate Can be 50-1000 sccm.

  Thereafter, an ashing process is performed as necessary. Thereby, the process residue etc. which generate | occur | produced by the etching process can be removed, and the coating-film 601a surface and the pad surface can be cleaned. As a result, the adhesive force of the adhesive layer 601 described later can be increased, and the bonding force of the bonding wire 70 to the pad can be increased.

Examples of the ashing treatment include plasma treatment and wet treatment using a chemical. Among these, the conditions for performing the plasma treatment are, for example, oxygen gas (O ₂ ), a mixture gas of oxygen gas (O ₂ ) and argon gas (Ar), or the like as the treatment gas, the output is 200 to 2000 W, and the treatment time. Is 0.2 to 15 minutes, and the gas flow rate is 50 to 1000 sccm.

[6] Back Grinding Step Next, as shown in FIG. 3G, a back grind film 90 is pasted on the coating film 601a. The back grind film 90 supports the wafer 201 during the back grind process, and suppresses occurrence of defects such as chipping and cracking in the wafer 201.

  Next, the back surface (the other surface side) of the wafer 201 is ground (back grinding process). Thereby, the broken line portion in FIG. 3H is removed, and the thickness of the wafer 201 can be reduced. As a result of this grinding, the thickness of the wafer 201 is reduced to about 20 to 100 μm although it varies depending on the original thickness.

  For this grinding, for example, a device called a back grinding wheel is used.

  In addition, the coating film 601a obtained by the photosensitive resin composition of the present invention can cut out the adhesive layer 601 that expresses sufficient adhesive force with the semiconductor chip 20. In addition, the coating film 601a obtained from the photosensitive resin composition of the present invention also exhibits sufficient adhesive force to the back grind film 90. Therefore, by sticking the back grind film 90 on the coating film 601a, the back grind film 90 can reliably support the coating film 601a and the wafer 201, and the above-described back grinding process can be performed with high accuracy. it can. For this reason, it is possible to realize the semiconductor chip 20 in which the thickness variation is small and the inclination or the like hardly occurs when stacked.

  In the case of this embodiment, the coating film 601a is formed on the wafer 201 subjected to the back grinding process, and the back grinding process is performed in that state. As described above, the coating film 601a has mechanical characteristics that can reliably bond the semiconductor chips 20 to each other. Therefore, the coating film 601a not only intervenes between the wafer 201 and the back grind film 90, but also has a function of mechanically supporting the wafer 201. In addition, since the coating film 601a is formed on the wafer 201 in a liquid state and then cured, the adhesion with the wafer 201 is good. Therefore, by performing the back grinding process on the wafer 201 in a state where the coating film 601a is formed, a more uniform process can be performed.

[7] Dicing Step Next, the wafer 201 is subjected to a dicing process. As a result, the wafer 201 is cut into a plurality of semiconductor chips 20 and separated into individual pieces.

  In the dicing process, the wafer 201 is attached to a dicing die attach film or a dicing film. This dicing die attach film or dicing film fixes the wafer 201 during the dicing process.

  FIGS. 3 (i1) and 3 (i2) are diagrams showing an example in which a dicing film 100a is attached to the back side of the wafer 201 ground in the back grinding process. FIG. 3 (i1) illustrates a wafer 201 and the like for cutting out the semiconductor chip 20 used for the lowermost layer (the layer closest to the package substrate 30) of the chip stack 200, while FIG. i2) illustrates the wafer 201 and the like for cutting out the semiconductor chip 20 used in a portion other than the lowermost layer of the chip stack 200.

  In FIG. 3 (i1), the dicing die attach film 100 which is a laminated body of the dicing film 100a and the die attach film 100b is affixed on the back surface of the wafer 201, while in FIG. The dicing film 100a is affixed on the back surface.

  Next, as shown in FIGS. 4 (j1) and 4 (j2), the back grind film 90 is peeled off from the coating film 601a.

  Next, a dicing process is performed on the wafer 201 provided with the coating film 601a. In the dicing process, as shown in FIGS. 4 (k1) and 4 (k2), the dicing blade 110 reaches the dicing film 100a. As a result, the coating film 601a, the wafer 201, and the die attach film 100b are separated into individual pieces, and the adhesive layer 601, the semiconductor chip 20 (first semiconductor element), and the adhesive layer 101 are laminated as shown in FIG. 4 (k1). The individual piece 21 is cut out. Similarly, the coating film 601a and the wafer 201 are separated into individual pieces, and as shown in FIG. 4 (k2), the individual pieces 22 formed by laminating the adhesive layer 601 and the semiconductor chip 20 (second semiconductor element) are cut out.

  In the present embodiment, a case has been described in which a plurality of semiconductor chips 20 are cut out by performing a dicing process on a wafer 201 configured to include a plurality of semiconductor chips 20. However, the present embodiment is limited to such a case. For example, a plurality of semiconductor chips 20 separated in advance may be used. When using a plurality of semiconductor chips 20 that have been separated into pieces in advance, the dicing process can be omitted. Further, when the wafer 201 and the semiconductor chip 20 are thin from the beginning, the back grinding process can be omitted.

  Further, the process order of the back grinding process and the dicing process is not limited to the order described above, and may be reversed. That is, the back grinding process may be performed after the wafer 201 is subjected to the dicing process.

[8] Mounting Process FIG. 4 (L1) and FIG. 4 (L2) are diagrams showing an example in which the cut piece 21 and the piece 22 are picked up by the collet 121 of the bonding apparatus 120, respectively.

  First, the individual piece 21 is picked up by the collet 121 of the bonding apparatus 120 and is crimped (mounted) on the package substrate 30. At this time, the back surface of the semiconductor chip 20 and the package substrate 30 are bonded via an adhesive layer 101 as shown in FIG. In addition, this contact bonding layer 101 may be comprised with the hardened | cured material of the photosensitive resin composition of this invention other than the piece of the die attach film 100b, for example.

  Then, the piece 22 is crimped | bonded on the piece 21 mounted previously. Thereby, as shown in FIG. 5B, two semiconductor chips 20 can be stacked via the adhesive layer 601. Thereafter, by repeating this step, as shown in FIG. 5C, a chip stack 200 in which a large number of semiconductor chips 20 are stacked is obtained. At this time, by stacking the semiconductor chips 20 while shifting the positions thereof, a region to which the bonding wire 70 is connected (a region corresponding to the opening 601b of the coating film 601a) can be secured.

  Further, when the semiconductor chip 20 is mounted, the adhesive layer 601 is heated. Thereby, sufficient adhesive force is expressed in the adhesive layer 601, and the semiconductor chips 20 can be firmly bonded to each other. In this case, the heating temperature is preferably about 30 to 150 ° C. Moreover, it is preferable that the crimping | compression-bonding load at the time of mounting is about 0.1-100N, and the crimping | compression-bonding time is about 0.1-10 seconds.

  Thereafter, the electrode portion of each semiconductor chip 20 and the exposed portion of the wiring 34 of the package substrate 30 are connected by a bonding wire 70 as shown in FIG.

  And the semiconductor device 10 shown in FIG. 1 is obtained by shape | molding the mold part 50 so that the chip laminated body 200 may be covered.

  The molding of the mold part 50 can be performed by, for example, using a transfer molding machine and injecting a sealing material into the molding die. In that case, it is preferable that the temperature of the mold is about 130 to 250 ° C., the injection pressure is about 3 to 10 MPa, and the holding time after injection is about 10 seconds to 10 minutes.

  After mold release, the molded part 50 and the adhesive layer 601 can be finally cured by heating the molded body as necessary. In this case, the heating temperature is preferably about 130 to 250 ° C., and the heating time is preferably about 10 minutes to 10 hours.

  Although the present invention has been described above, the present invention is not limited to this. For example, an arbitrary component may be added to the photosensitive resin composition. Further, an arbitrary structure may be added to the semiconductor device.

  Next, specific examples of the present invention will be described.

Example 1
[1] (A) Synthesis of Alkali-Soluble Resin (Cyclic Olefin Resin A-1) A plurality of glass devices were prepared, and these were dried at 60 ° C. under 0.1 Torr for 18 hours. Thereafter, all glass equipment was installed in the glow box.

  Next, toluene (992 g), dimethoxyethane (116 g), 1,1-bistrifluoromethyl-2- (bicyclo [2.2.1] hept-2-ene-5 was added to one glass device (glass device X). -Yl) ethyl alcohol (hereinafter, HFANB) (148 g, 0.54 mol), ethyl 3- (bicyclo [2.2.1] hept-2-en-2-yl) propanate (hereinafter, EPEsNB) (20.7 g) 0.107 mol), 5-((2- (2-methoxyethoxy) ethoxy) methyl) bicyclo [2.2.1] hept-2-ene (hereinafter, NBTON) (61.9 g, 0.274 mol). Prepared. Then, purging was performed by flowing nitrogen for 30 minutes while heating these charged monomers at 45 ° C.

  In another glass device (glass device Y), EPEsNB (14.2 g, 0.073 mol) and NBTON (46.7 g, 0.159 mol) were mixed and purged with nitrogen. After the nitrogen purge was completed, bis (toluene) bis (perfluorophenyl) nickel (5.82 g, 0.012 mol) dissolved in 60.5 ml of toluene was put into the glass apparatus Y. At the same time, the monomer mixed in the glass apparatus X described above was added into the glass apparatus Y over 3 hours at such a rate as to keep it at a constant level for polymerization, thereby obtaining a reaction solution.

  Next, the reaction solution was dissolved in about 1 L of methanol / THF (= 4 mol / 5 mol) solution to remove unreacted monomers, and then sodium hydroxide / sodium acetate (= 4) at 60 ° C. for 4 hours. The ester was hydrolyzed with sodium hydroxide solution (.8 mol / 1 mol). Thereafter, methanol (405 g), THF (87 g), acetic acid (67 g), formic acid (67 g) and deionized water (21 g) were added, and the mixture was stirred at 50 ° C. for 15 minutes. When the stirring is stopped, the solution is separated into an aqueous layer and an organic layer. The upper aqueous layer is removed, and the organic layer is washed with a methanol / deionized water (= 390 g / 2376 g) solution three times at 60 ° C. for 15 minutes. did. And the obtained polymer was diluted in the solvent and solvent substitution was carried out. Thus, the polymer (cyclic olefin resin A-1) shown by Formula (7) was obtained.

The yield of cyclic olefin resin A-1 was 93.1%. The weight average molecular weight (Mw) of the cyclic olefin resin A-1 was 85,900. The molecular weight dispersion (PD) of the cyclic olefin resin A-1 was 2.52.

The composition of the cyclic olefin-based resin A-1 is as follows: ¹ H-NMR, HFANB is 45.0 mol%, 2- (bicyclo [2.2.1] hept-2-en-5-yl) propionic acid (Hereinafter, EPENB) was 15.0 mol%, and NBTON was 40.0 mol%.

In the above formula (8), l: m: n = 45: 15: 40.
[2] Production of photosensitive resin composition (A) Cyclic olefin resin A-1 (25.0 parts by mass) as an alkali-soluble resin obtained in [1], and (B) a photoacid generator Photoacid generator B-1 (4.0 parts by mass) as (C) Thermal crosslinking agent C-1 (5.0 parts by mass) as a thermal crosslinking agent, (D) Alkoxy as an alkoxysilane compound Silane compound D-1 (0.5 parts by mass), phenol compound E-1 (3.0 parts by mass) as a dissolution aid, antioxidant F-1 (0.5 parts by mass), and solvent (solvent ) As propylene glycol methyl ether acetate (60.5 parts by mass) to obtain a uniform photosensitive resin composition.

  The materials used in the photosensitive resin composition of Example 1 are shown below.

<Photoacid generator B-1>
A compound represented by the following formula (9) was prepared as the photoacid generator B-1.

<Thermal crosslinking agent C-1>
As the thermal crosslinking agent C-1, a compound represented by the following formula (10) was prepared.

<Alkoxysilane compound D-1>
As the alkoxysilane compound D-1, a compound represented by the following formula (11) (3- (2-glycidoxyphenyl) propyltrimethoxysilane) was prepared.

<Phenol compound E-1>
As the phenol compound E-1, a compound (2,2′-dihydroxydiphenylmethane) represented by the following formula (12) was prepared.

<Antioxidant F-1>
A compound (4,4′-di (α, α-dimethylbenzyl) diphenylamine) represented by the following formula (13) was prepared as the antioxidant F-1.

(Examples 2-8, Comparative Examples 1-5)
A photosensitive resin composition was obtained in the same manner as in Example 1 except that the materials constituting the photosensitive resin composition were changed to those shown in Table 1 and the contents thereof were changed to those shown in Table 1.

In addition, the material used with the photosensitive resin composition of each Example and a comparative example is shown below.
<Phenolic resin A-2>
Phenol in which m-cresol and p-cresol were mixed in a molar ratio (m-cresol: p-cresol) = 4: 6 in a 3 L four-necked flask equipped with a stirrer, a thermometer, and a heat exchanger. To 7000 parts of the class, 470 parts of a 37% formalin aqueous solution and 5 parts of oxalic acid were charged and reacted under reflux for 4 hours. Thereafter, dehydration was carried out under normal pressure to an internal temperature of 170 ° C., and dehydration / demonomerization was further carried out to 200 ° C. under a reduced pressure of 9.3 × 10 3 Pa.
660 parts of phenol resin A-2 represented by the following formula (14) of 00 was obtained.

<Alkoxysilane compound D-2>
As the alkoxysilane compound D-2, a compound represented by the following formula (15) (N-phenyl-3-aminopropyltrimethoxysilane) was prepared.

<Alkoxysilane compound D-3>
As the alkoxysilane compound D-3, a compound represented by the following formula (16) (3- (4-aminophenyl) propyltrimethoxysilane) was prepared.

<Alkoxysilane compound D-4>
As the alkoxysilane compound D-4, a compound represented by the following formula (17) (3- (4-hydroxyphenyl) propyltrimethoxysilane) was prepared.

<Alkoxysilane compound D-5>
As the alkoxysilane compound D-5, a compound (3- (N-methyl-N- (4-pyridyl) amino) propyltrimethoxysilane) represented by the following formula (18) was prepared.

<Alkoxysilane compound D-6>
As the alkoxysilane compound D-6, a compound represented by the following formula (19) (3- (3-phenylureido) propyltriethoxysilane) was prepared.

<Alkoxysilane compound D′-1>
Alkoxysilane compound D′-1 ((D ′) Alkoxy in which functional group (X) showing Bronsted acidity and functional group (A) showing reactivity are not directly bonded to the aromatic ring due to proton dissociation in alkali-soluble resin As the silane compound, a compound represented by the following formula (20) (3-aminopropyltrimethoxysilane) was prepared.

<Alkoxysilane compound D'-2>
Alkoxysilane compound D′-2 ((D ′) Alkoxy in which functional group (X) showing Bronsted acidity and functional group (A) showing reactivity are not directly bonded to the aromatic ring due to proton dissociation in alkali-soluble resin As the silane compound, a compound represented by the following formula (21) (3-aminobutyltrimethoxysilane) was prepared.

<Alkoxysilane compound D'-3>
Alkoxysilane compound D′-3 ((D ′) Alkoxy in which functional group (X) showing Bronsted acidity and functional group (A) showing reactivity are not directly bonded to an aromatic ring due to proton dissociation in an alkali-soluble resin As the silane compound, a compound represented by the following formula (22) (3-aminooctyltrimethoxysilane) was prepared.

<Alkoxysilane compound D′-4>
Alkoxysilane compound D'-4 ((D ') Alkoxy in which functional group (X) showing Bronsted acidity and functional group (A) showing reactivity are not directly bonded to an aromatic ring due to proton dissociation in an alkali-soluble resin As the silane compound, a compound represented by the following formula (23) (3-
Phenyltrimethoxysilane) was prepared.

[3] Preparation of test piece for evaluation First, the photosensitive adhesive composition was applied on a semiconductor chip made of silicon, and prebaked at 120 ° C. for 5 minutes. This obtained the coating film.

  Next, the obtained coating film was subjected to a heat treatment at 150 ° C. for 40 minutes.

Next, an etching process and an ashing process were sequentially performed on the heat-treated coating film. The etching process uses a mixed gas of fluorine compound gas (CF ₄ ), argon gas (Ar) and oxygen gas (O ₂ ), the output is 2500 W, the time is 6 minutes, and the CF ₄ flow rate / Ar flow rate / O ₂ flow rate is The ashing process was performed using a mixed gas of O ₂ and Ar, the output was 600 W, the time was 12 minutes, and the O ₂ flow rate was 200 sccm.

  Next, another semiconductor chip or glass chip was stacked through the coating film, and was pressed with a load of 10 N for 5 seconds while heating at a temperature of 150 ° C.

In this way, an evaluation test piece in which two semiconductor chips or a semiconductor chip and a glass chip were bonded via an adhesive layer was produced.
[4] Evaluation of photosensitive adhesive composition and test piece for evaluation [4.1] Evaluation of substrate adhesion during development First, the photosensitive adhesive composition used in each example and each comparative example was made of silicon. It apply | coated on the semiconductor chip and 120 degreeC and the prebaking for 5 minutes were performed. Thereby, a coating film having a thickness of 10 μm was obtained.

Next, the obtained coating film was subjected to an exposure treatment through a line and space pattern mask having a width of 100 μm. In addition, this exposure process was performed by irradiating the light whose wavelength is 365 nm and light intensity is 5 mW / cm < ² > in the air, changing time for every coating film.

  Next, the exposed coating film was developed with an alkali developer (2.38% tetramethylammonium hydroxide aqueous solution) at 23 ° C. for 40 seconds, and then rinsed with pure water for 20 seconds. An opening of 100 μm in the coated film (adhesive layer) after development was observed with an optical microscope, and the degree of pattern peeling was performed based on the following evaluation criteria.

<Evaluation criteria>
A: No pattern peeling.

  ◯: Pattern peeling is less than 30%.

  Δ: Pattern peeling is 30% or more and less than 50%.

X: Pattern peeling is 50% or more.
[4.2] Evaluation of patterning property First, the photosensitive adhesive composition used in each example and each comparative example was applied on a silicon semiconductor chip, and prebaked at 120 ° C. for 5 minutes. Thereby, a coating film having a thickness of 10 μm was obtained.

Next, the obtained coating film was subjected to an exposure treatment through a line and space pattern mask having a width of 100 μm. In addition, this exposure process was performed by irradiating the light whose wavelength is 365 nm and light intensity is 5 mW / cm < ² > in the air, changing time for every coating film.

Next, the exposed coating film was developed with an alkali developer (2.38% tetramethylammonium hydroxide aqueous solution) at 23 ° C. for 40 seconds, and then rinsed with pure water for 20 seconds.
A 100 μm opening of the developed coating film (adhesive layer) was observed with an optical microscope, and the residual film ratio of the unexposed area defined as follows was 90% or more, and The minimum exposure amount (unit: mJ / cm ² ) when the remaining film ratio was 0% was determined, and the patterning property was evaluated based on the following evaluation criteria.

Residual film ratio = 100 × film thickness after development of unexposed area / film thickness after pre-baking <Evaluation Criteria>
A: Minimum exposure is less than 300 mJ / cm ² .
A: Minimum exposure amount is 300 mJ / cm ² or more and less than 450 mJ / cm ² .
△: the minimum exposure amount is 450 mJ / cm ² or more 600 mJ / cm less than ^2.
X: Minimum exposure amount is 600 mJ / cm ² or more.
[4.3] Evaluation of adhesiveness About the test piece for evaluation in which the obtained semiconductor chip and glass chip were bonded, the void was observed from the upper surface of the glass chip using an optical microscope, and the void occupancy was calculated. Evaluation was made based on the following evaluation criteria.

Void occupancy = 100 × void area / glass chip area <Evaluation Criteria>
A: The adhesiveness is very high. (Void occupancy is 0-20%)
○: Adhesiveness is high. (Void occupancy is 20-50%)
Δ: Low adhesiveness. (Void occupancy is 50-70%)
X: Adhesiveness is very low. (Void occupancy is 70-100%)
[4.4] Evaluation of hygroscopicity About the test piece for evaluation to which the obtained two semiconductor chips were bonded, a sample subjected to high temperature and high humidity treatment under conditions of 85 ° C., 85% RH, 24 hours, and high temperature Using a Dage 4000 (manufactured by Daisy Japan Co., Ltd.) for a sample not subjected to high-humidity treatment, when the semiconductor chip is pushed horizontally with a shear tool from the side (side surface) of the semiconductor chip, and the joint surface between the chips is broken The die shear strength per chip was measured. The chip size was 4 mm × 4 mm.

  And the deterioration rate was computed by the following formula from the measured die shear strength, and it evaluated based on the following evaluation criteria.

Degradation rate = 100 × (1-Die shear strength of high temperature / humidity treated sample / die shear strength not subjected to high temperature / humidity treatment)
<Evaluation criteria>
A: Extremely high hygroscopicity. (Deterioration rate is 0-20%)
○: High hygroscopicity. (Deterioration rate is 20-50%)
Δ: Hygroscopicity is low. (Deterioration rate is 50-70%)
X: The hygroscopicity is very low. (Deterioration rate is 70-100%)

  As is apparent from Table 1, it was confirmed that the photosensitive resin composition and the test piece for evaluation of each example had sufficient adhesion between the wafer and the coating film. Further, the coating film used in each Example had a small minimum exposure amount at which the remaining film ratio of the exposed portion after development was 0%, and the patterning property was good. Furthermore, it was confirmed that the test piece for evaluation of each example had good adhesion between the coating film (adhesive layer) and the semiconductor chip and high moisture absorption.

4 Mask 10 Semiconductor device 20 Semiconductor chip 21 Piece 22 Piece 30 Package substrate 31 Core substrate 32 Insulating layer 33 Solder resist layer 34 Wiring 35 Conductive via 50 Mold part 70 Bonding wire 80 Solder ball 90 Back grind film 100 Dicing die attach Film 100a Dicing film 100b Die attach film 101 Adhesive layer 110 Dicing blade 120 Bonding device 121 Collet 200 Chip laminate 201 Wafer 601 Adhesive layer 601a Paint film 601b Opening

Claims (8)

(A) an alkali-soluble resin having a functional group showing Bronsted acidity by proton dissociation;
(B) a photoacid generator;
(C) a thermal crosslinking agent;
(D) an alkoxysilane compound;
A photosensitive resin composition comprising:
The (D) alkoxysilane compound has an aromatic ring, and the functional group showing reactivity with the functional group showing Bronsted acidity by proton dissociation is directly bonded to the aromatic ring. Resin composition. The photosensitive resin composition according to claim 1, wherein the (D) alkoxysilane compound is represented by the general formula (1).

(Wherein X is a carbon atom or nitrogen atom, R ₁ is a functional group that is reactive with a functional group that exhibits Bronsted acidity by proton dissociation, R ₂ is an alkylene group having 1 to 10 carbon atoms, R ₃ and R ₄ represents an alkyl group having 1 to 3 carbon atoms, and t represents 0 to 3) The photosensitive resin composition according to claim 1, wherein the (D) alkoxysilane compound is represented by the general formula (2).

(Wherein X is a carbon atom or nitrogen atom, R ₁ is a functional group that is reactive with a functional group that exhibits Bronsted acidity by proton dissociation, R ₂ is an alkylene group having 1 to 10 carbon atoms, R ₃ and R ₄ represents an alkyl group having 1 to 3 carbon atoms, and t represents 0 to 3) The photosensitive resin composition according to claim 1, wherein the thermal crosslinking agent (C) is a compound having a glycidyl group. The photosensitive resin according to any one of claims 1 to 4, wherein the alkali-soluble resin (A) having a functional group that exhibits Bronsted acidity by proton dissociation is a norbornene monomer homopolymer or copolymer. Composition.
The functional group of the alkali-soluble resin having a functional group that exhibits Bronsted acidity by proton dissociation (A) is a carboxyl group or —C (OH) — (CF ₃ ) _2. The photosensitive resin composition according to item. The semiconductor element using the photosensitive resin composition as described in any one of Claims 1 thru | or 6. A stacked semiconductor device in which the semiconductor elements of claim 7 are stacked.